Friends' cigarette use a bigger factor in middle school than in high school, research shows

SUNDAY, April 28 (HealthDay News) -- Peer pressure to smoke may be more influential for kids in middle school than for older students, a new study reports.

Although their friends' smoking behavior may hold less sway for teens over time, researchers said parents seem to remain influential over their children's smoking behavior throughout high school. They suggested that smoking intervention programs focused on peer pressure to smoke would be more effective for students in middle (or junior high) school than high school, and parents could provide another possible anti-smoking strategy.

Based on previous research that looked at social development, "we thought friends would have more influence on cigarette use during high school than junior high school," study author Yue Liao, a student with the Institute for Health Promotion and Disease Prevention Research at the Keck School of Medicine of the University of Southern California, said in a university news release.

"But what we found was friends have greater influence during junior high school than high school. We think the reason may be that friends' cigarette use behavior may have a stronger influence on youth who start smoking at a younger age," Liao continued. "During high school, cigarette use might represent the maintenance of behavior rather than a result of peer influence."

For the study, the researchers examined information on about 1,000 teens involved in the Midwestern Prevention Project, the longest-running substance use prevention, randomized controlled trial in the United States. Randomized controlled studies are considered the gold-standard for research.

The students were first questioned in the seventh grade when they were 11 years old. They were reassessed after six months, and then once every year until they were in the 12th grade.

The participants were asked how many of their close friends and parents (or two important adults in their lives) smoked cigarettes. The students were also asked how many cigarettes they had smoked in the past month. Over the course of the study, the influence of the students' friends and parents was analyzed to determine if it changed as the students got older.

The investigators found that kids' smoking behavior is significantly affected by the habits of their peers and their parents in both middle school and high school. The influence of friends, however, is stronger in middle school. Although parents' influence started to decrease in the final two years of high school, it did not change between middle school and high school.

Among students in grades 9 and 10, girls were more affected by their friends' smoking behavior than boys, the researchers noted. As they advanced to 10th and 12th grades, however, friends and parents had less influence on girls. Meanwhile, boys at this age were increasingly swayed by their friends' smoking habits.

"Boys tend to foster friendship by engaging in shared behaviors, whereas girls are more focused on emotional sharing," Liao explained. "So, it is possible that boys are adopting their friends' risky behaviors, like smoking, as the groups grow together over time."

The study authors concluded their findings could aid in the development of teen anti-smoking programs.

"We observed a big dip in friends' effect on smoking behavior from eighth to ninth grade. Thus, the first year of high school represents an opportunity for interventions to counteract peer influence and to continue to target parents as their behavior remains influential through the end of high school," Liao said in the news release. "In addition, teaching students refusal skills during junior high school could be effective in decreasing cigarette use at the beginning of high school. Programs could also promote positive parenting skills to protect children from deviant peer influence."

The researchers noted that more research is needed to explore the influence of siblings on teen smoking.

The study was published in the April 12 issue of the Journal of Adolescent Health.

More information

The U.S. Centers for Disease Control and Prevention has more about teen smoking.